Vehicle hoist



Feb. 27, 1951 N. R. SLASOR ET AL VEHICLE HOIST 2 Sheets-Sheet 1 Filed April 21, 1949 0 Cuddlove/2mm Job Feb 27, 1951 N. R. SLASOR ET AL VEHICLE HOI.ST

2 Sheets$heet 2 Filed April 21, 1949 dob/9 Caddy.

Patented Feb. 27, 195i TET GFICE ATES Manitoba, Canada, assignors to The Manitoba Bridge And iron Works Limited, Winnipeg,

Manitoba, Canada [application Aprii 21, 1949, Serial No. 88,763

Glaims.

der pan within which grain hoists are commonly sunk, and within the extremely confined and flooded area thereof, detach the lower end-plate of the cylinder for this purpose.

A positive advantage flowing from, the elimination of the necessity set forth in the last preceding paragraph resides in location of the U- venting rotation of the piston during the last stage of its descent into the cylinder which eliminates the possibility of misalignment of the cradle secured to the top of the piston with the surrounding floor structure.

With the foregoing objects in view, and such other objects and advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, our invention consists essentially in the arrange-- ment and construction of parts all as hereinafter more particularly described, reference being had to the accompanying drawings, in which:

Figure l is a vertical and predominantly ,sec-

leather recess near the upper end of the cylinder, tional representation of the wholly pneumatically the formation of the cylinder in two parts operated embodiment of the present invention. hereinafter referred to as a head-casting and a Figure 2 is a fragmentary cross-sectional eletrunk section, the trunk-section being separable ation depicting the trunk-section of the cylinfrom the head-casting on the occasions of U- cler of this invention separably lowered from the leather replacement following the elevation of head section on an occasion of U-leather replacethe piston as will be described in greater detail ment. hereinafter. Figure 3 is a side elevation of the embodiment A further object is to provide a hoisting cylinof Figure 1 as viewed from the right-hand side der and iston combination wherein the U- of Figure v1. leather being located on a plane near that Figure 4 is a fragmentary side elevation of the reached by the lower end of the piston at the embodiment of Figure l substantially as Viewed upper end of its travel and retained within a at LA! of'Figurel'but with the piston somewhat recess in the cylinder rather than the piston so raised. that the piston and cylinder may be in concen- Figure 5 is a side elevation partly fragmented trio spaced relationship below the level of the into cross-sectional representation of the hoist leather thereby eliminating the expensive necesshown in Figure '1 modified to contain a body of sity for the interior grinding of the cylinder wall. oil, and to be operated pneumatically "in cooper- A further object of the present invention is ation with such body. to provide an improved lubricating arrangement In the drawings like characters of reference comprising the provision of an annular oil resindicate corresponding parts in the different ervoir between the piston and cylinder at the upfigures. per end of the latter. Grain elevator vehicle hoists as generally des- A further object is to provide (in a modificaignated by the reference numeral l in the action thereof) an assembly of the character herecompanying figures are commonly sunk within a Within described wherein an oil body co-acts with 40 well or cylinder pan so that the conventional the pneumatic power-supplying agency to reduce cradle 2 which is secured to the upper end of the factor of undesirable resiliency in the pisthe piston collectively designated 3, is flush with ton, as well as to provide for a steadier subsidence the surrounding floor level so that the front ends of the piston under load, and to ensure against of trucks may be driven thereonto prior to elethe possibility of a sudden drop as can somevation and precipitation 0f the loadtimes take place in wholly pneumatically operated lifting arrangements.

A further object is to provide means for permitting the escape of air in the event that the piston stop arrangements herein described should sheer off when the piston has reached the normal upper end of its travel, so as to provide safety means preventing any further substantial rise,

A further object is to provide in combination witha device as herein described means for pre- This well or cylinder pan is several feet deep and has a diameter only just sufiicientl-y greater than the diameter of the cylinder collectively designated to accommodate a man, who, in the periodical cleaning out of the cylinder pan must work under very confined conditions.

It is also necessary to descend into the cylinder pan on the occasions of replacing worn U- leather rings, whereby a pneumatic seal is retained between the piston and cylinder. These 3 rings are commonly retained in an annular recess extending around the lower end of the piston, and to gain access thereto, a bottom endplate must be unscrewed from the cylinder.

It is a primary purpose of the present invention to eliminate the necessity for the particular operation above described, and proceeding therefore to describe the invention depicted in the accompanying figures in detail, it is first to be explained that the cylinder 4 is divided into two main components in the form of what is herein collectively designated as a head-casting and a trunk-section 6.

The head-casting 5 is mounted upon a conventional square plate I supported on the conventional beams 8, 9, and E5, and at the lower end thereof is annularly rabbeted as at H to receive the upper end i2 of trunk-section 6.

lhe joint for junction l3 between the upper end flange l2 and the lower head-casting flange I4 is sealed by a plurality of spaced bolts 55 (and by this term their functional equivalent is intended to be understood), and by a diametrically situated pair of longer bolts l5.

The apertures in the flange I2 through which the bolts l6 extend are plain and of a diameter such that the bolt l5 be moved freely end- Wise therethrough. Only the apertures in alignment therewith in the flange Id are screwthreaded, and consequently, following the withdrawal of the several shorter bolts i5 rotatably downwards until they have disengaged the apertures provided therefor in fiange id, it will be apparent that rotation of the bolts |6 will permit trunk-section 6 to separate downwardly from head-section 5 at the junction l3.

Within the flange l2 of trunk-section 6 is an annular recess Ii within which is accommodated a conventional U-leather sealing ring l8, and from the foregoing it will readily be apparent that when the trunk-section B has been separately lowered with respect to head-castin 5 as aforesaid, access is gained to the leather and recess. A worn leather may therefore readily be removed after it has been cut. However, it cannot be removed in ring form, or replaced by a new endless ring unless and until piston 3 has been raised to an extent such that the lower end thereof occupies a plane above that of the leather 'rality of air discharge safety ports 22 are provided for use in the event of the piston over-rising in its upward stroke as will be hereinafter explained.

Secured to one side of head-casting 5 is a guide assembly collectively designated 23 through the open ended guiding aperture 24 whereof extends a pendant channel bar 25 suspended from a length of chain 26 anchored to the top endplate 27 of piston 3. Positioned medially upon the length of bar 25 is a latching recess 28 of the configuration clearly depicted in Figures 1 and 3, and at the lower end is positioned a vertically elongated stop block 29 the upper end 39 whereof is intercepted by the region 3| of guide 4 23 when the bar is lifted with the raising of the piston 3.

An air conduit nipple 3| communicates with passage 32 in guide assembly 23 within which passage a shot bolt 33 having a piston 3 2 on the end thereof is positioned. The aforesaid shot bolt is engageable with recess 28 upon the introduction of air into the nipple 3| whereby piston 3 may be stopped during its ascent. In order to prevent rotation of the piston during the last stages of its descent into cylinder 4 so that the cradle 2 will not skew and hit the surrounding floor, a pair of vertically disposed, spaced and parallel flanges 35 are provided, being secured to or formed integral with head-casting 5 a pair of outwardly flared lead-in portions 35 being positioned coterminously at the upper ends of the aforesaid flanges to facilitate the entry therebetween of a follower 31 in the form of a roller journalled in the lower end of a downwardly depending arm 38 secured to end-plate 2'], being thus connected to piston 3 and movable therewith.

By reference to the accompanying Figure 1 it will be observed that piston 3 is spaced from the trunk-section 6 of cylinder 4 below the plane of U-leather l8, and spanned at the lower end thereof by a bottom end-plate 39 which, for wholly pneumatic operation is provided with a plug to close the central aperture 4|. Similariy, in this context it will be noted that the lower end of trunk-section 6 is provided with a plug .2 to seal the aperture 43. Thus, when ompressed air is introduced through either side the double-ended nipple 44 (see Figures 1 and u}, the air will travel downwardly within the space between the piston and trunk-section to expand in the chamber 45 and force piston 3 upwardly.

As previously indicated, the upper end of the normal travel of piston 3 is determined when the upper end 30 of block 29 comes up against the underside 3| of guide assembly 23. If however through some mischance block 29 is sheered off so that the piston continues on up past the plane of U-leather l8, and the plane of the escape ports 22, air in sufficient volume to prevent further elevation of the piston will escape through the ports 22.

At this point it is to be explained that on the occasions of replacing a worn U-leather l8, it is desirable to elevate piston 3 to a slight supplementary extent so that it will not be necessary to create too wide a gap 46 at the junction of the flanges |2 and I4 when separating trunksection 5 from head-casting 5. To amplify in this context, it should be explained that at the limit of the normal upward stroke of piston 3, the lower end thereof will be slightly below the plane of U-leather I8. However, the further increment of elevation resorted to on the occasions of replacing worn leathers is designed to bring the lower end of piston 3 approximately coincident with the plane of the U-leather prior to the downward separation thereof from flange I4.

To accomplish this bolt ill is removed from block 22, and the said block rotated to degrees about the bolt 58. Since block 29 is oblong, it will now be apparent that side 49 will be intercepted by the region 3| of guide assembly 20. Thus the effective length of bar 25 is increased and so piston 3 may be caused to travel a short supplementary distance upwards, and in that position be chocked as by wooden beams or the like placed thereagainst so that the piston is supported on the beams which extend between the underside projecting or flange portion 58 of endplate 2?, and the upper surface of the head-casting flange 5!.

After piston 3 has been maximall elevated as aforesaid, trunk-section may be separated and lowered as depicted in Figure 2 from which it will clearly be apparent that a worn leather may not only be removed intact, but a new leather inserted, since the lower end of piston 3 is now clear above the plane of the leather.

In the accompanying Figure 5 the present invention has been illustrated as adapted for operation by compressed air in combination with an oil body. In this connection it is to be explained that no material structural differences are involved and in manufacture it will be the practice to make each unit adaptable either for wholly pneumatic use or for'pneumatic use in combination with the oil body. Proceeding therefore to describe the arrangements resorted to in the use of oil the following is submitted:

Plug i2 is removed from the lower end of the trunk-section i3 and a compressed air pipe 52 is inserted through aperture d3 which is afterwards circumferencially sealed. Plug it is also removed from aperture ll in the bottom end-plate 39 of piston 23. Pipe E2 extends upwardly through the aperture "i5 and it is to be noted that this aperture is of greater diameter than that of the pipe so that oil may seep past or in other words communicate between the chamber 4-5 and the interior d6 of the piston.

When an oil body is used in co-action with compressed air, it is unnecessary to keep reservoir [9 filled with 011. Also it is to be explained that before filling with oil, the ports 22 are sealed. However, the bleeder port 53 which is sealed when the unit is operated by compressed air only, is temporarily opened to bleed off discharge air during the filling of the piston, the chamber 5 and the space between the piston and trunk-section with oil through the filler plug 54. When the unit has been fill-ed to approximately the point illustrated in the accompanying Figure 5, bleeder port 53 may be rescaled.

From Figure 5 it will be perceived that an air trap 55 exists between the oil body surface 56 and top endplate 2i, and into this space compressed air is pumped through pipe 52. results in the elevation of piston 3 with a slow steady thrust as oil is exchanged from the interior of the piston into the volumetrically variable chamber @5. When it is desired to lower the piston, air above the oil level 56 is allowed to escape through pipe 52, and thus the piston will move non-resiliently and steadily downward as oil seeps from chamber 45 into the piston interior.

In conclusion it is to be noted that chain 26 is provided to connect bar 25 to top end-plate 2? instead of directly connecting the bar to the plate, so as to accommodate the limited rotary movement which takes place and is caused by the action of the vehicle on the cradle 2. It is also to be noted that the cylinder 4 is suitably braced against lateral movement by the band 57, which however is free of the trunk section to allow the separation described, and the diagonals and braces 58 and 59 respectively.

Since many modifications can be made in the invention herein described and since the accompanying drawings have been prepared only to illustrate the relative arrangement and in- This teraction of parts and not with regard to accuracy of dimensions for manufacturing purposes which in view of this disclosure we consider to entail merely mechanical skill together with the skill of the mechanical draftsman, and since many apparently widely different embodiments of this invention may be made within the spirit and scope of the accompanying claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense and we desire only such limitations placed thereon as justice dictates.

What we claim as our invention is:

l. A vehicle hoist for rain elevators and th like comprising in combination a cylinder closed at the lower thereof, a hoisting piston within said cylinder, said cylinder embodying a headcasting a lk-SECtlQll, said head castir" being in cotei nous end alignment with :1d above the upper end of said trunk section and being separably connected thereto, an annular recess in said cylinder adjacent the junction of said headmasting trunk. section, and means for separating sai trunksection from said head-casting at said junction to limited extent lowering the trunksection the replacement of U-leather rings in said recess following the elevation of said piston to an extent such that the lower end thereof above: the plane occupied by said leather in situ.

2. A vehicle hoist for grain elevators and the like comprising combination a cylinder closed at t is lower hereof, a hoisting piston within said cylinder, said cylinder embodying a headcasting a trunk-section bolted pendant to and below said head-casting in coterrninous end alignment therewith, an annular leather seating recess in said cylinder adjacent the junction of said head-casting and said trunlnsection, and means for separating said trunk-section from said head-casting at said junction to a limited extent by slackening the bolts connecting said headcasting and said trunk-section allowing said trunk-section to separate downwardly from said head-casting at said junction in the replacement of U-leather rings in said recess following the elevation. of said piston to an extent such that the lower end thereof is above the plane occupied by said leather in situ.

3. The device according to claim 1 in which said U-leather recess is formed in said trunksection.

4. The device according to claim 2 in which said U-leather recess is formed in said trunksection.

5. A vehicle hoist for grain elevators and the like comprising in combination a cylinder closed at the lower end thereof, a hoisting piston within said cylinder, said cylinder being formed of at least two parts, one of said parts being immovable, the other having an annular leather seating recess formed therein, said latter part being sealably united to the immovable part but separable therefrom to facilitate the removal of a worn U-leather ring and the replacement thereof following the elevation of said piston to an extent such that the lower end thereof occupies a plane above that occupied at the upper end of the normal piston stroke and above the plane occuplied by said U-leather in situ.

6. A vehicle hoist for grain elevators and the 'ke comprising in combination a cylinder closed at the lower end thereof, a hoisting piston within said cylinder, said cylinder embodying a headcasting, and a trunk-section sealably attached pendant to and below said head-casting in coterminous end-alignment therewith, an annular leather seating recess in said cylinder adjacent the junction thereof with said head-casting, means for normally elevating said piston to a point such that the lower end thereof is on a plane slightly below that occupied by said recess, means operable on the occasions of U-leather replacement for elevating said piston a predetel-mined additional distance, and means for seD- arating said trunk section from said head-casting on the occasions aforesaid at said junction to a limited extent by lowering the trunk-section to an extent such that said leather is accessible and a new leather may be inserted below the elc vated lower end of said piston following the removal of the worn leather.

7. The device according to claim 6 in which said means for elevating said piston a predetermined additional distance comprises in combination a vertical bar external of, adjacent to, and parallel with said cylinder the upper end whereof is attached to the head of said piston, an immovable guide through which said bar may move with the upward and downward strokes of said piston, an elongated stop-block attached to the lower end of said bar, the upper end there of being intercepted by said guide to terminate the upward normal stroke of said piston, said block being rotatable through the arc of a circle from its normal position such that the distance from the upper extremity thereof in its rotated position to the point of interception by said guide when the bar is in its lowermost position, is increased.

8. The bar according to claim 7 which is suspended from a length of chain anchored to the head of said piston to permit limited rotary motion of said piston.

9. In a vehicle hoist for grain elevators and the like, a pendant cylinder having a closed lower end, a piston therewithin, and means for preventing rotation of said piston during the last stage of its descent into said cylinder comprising a pair of substantially vertical, spaced and parallel flanges on the external surface of the upper end of said cylinder, an outwardly and upwardly flared lead-in at the upper end of said pair of flanges, a downwardly projecting arm connected to the upper end of said piston and capable of overlying said pair of flanges, and a follower on said arm engageable with and subsidable between said flanges.

10. In a vehicle hoist for grain elevators and the like, a cylinder having a closed lower end, a piston therewithin, an annular U-leather recess in said cylinder near the plane occupied by the lower end of said piston at the upper end of its stroke, said piston and cylinder being spaced below said recess, a body of oil within said piston and filling the space between said piston and cylinder up to the level of said leather, an apertured bottom end plate spanning said piston, a compressed air pipe extending through the base of said cylinder, through said end plate and upwardly through said piston, said pipe opening on or above the oil level therewithin, a top endplate closing the upper end of said piston, said aperture in said bottom end-plate permitting the seepage of oil therethrough around said pipe.

NICHOLAS R. SLASOR. JOHN CUDDY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,624,151 Shevlin Apr. 12, 1927 1,759,670 Stukenborg May 20, 1930 2,288,511 Bratz et a1 June 30, 1942 FOREIGN PATENTS Number Country Date 24,890 Great Britain Nov. 16, 1904 

